Position measurements

Position measurements

1. Central

   • Mean
     • all values must be summed and then divided by the total number of observations
     • is known as arithmetic mean or average
   • Mode
     • Value of the data set having a higher absolute frequency
     • most repeated value of a dataset.
     • count the number of times each data appears in the sample
     • statistical mode or modal value.
     • Unimoda Mode
     • Bimodal Mode
     • Multimodal mode
   • Median
     • average value of all ordered data from lowest to highest
     • divides the entire dataset into two equal parts.
     • The calculation of the median depends on whether the total number of data is even or odd
     • N is the total number of sample data and Me is the median.

2. Not central

   • Percentiles
     • values that divide a sorted data set
       • one hundred equal parts
     • a percentile indicates the value below which a percentage of the data set is located.
     • are represented by the capital letter P
   • Deciles
     • nine values that divide a sorted data set
       • ten equal parts
       • 10%, 20%, 30%,…
       • are represented by the capital letter D
   • Quintiles
     • four values that divide a sorted data set
       • five equal parts.
         • 20%, 40%, 60% and 80%
     • symbol of quintiles is the capital letter K
       • can also be represented by the letter Q
   • Quartiles
     • Divide a sorted data set
     • are represented by a capital Q
     • For equal parts
     • three values that divide a set
       • 25%, 50% and 75%